Brachymyrmex

Brachymyrmex

is a formicine genus comprising some of the world's smallest ants. These diminutive ants- sometimes called "rover ants"- are native throughout the Americas, but several species have traveled to other parts of the world with human trade.

Brachymyrmex patagonicus workers take nectar from a barrel cactus. Cacti provide ants with food in exchange for protection from pests, but non-native species such as these rover ants may not provide the same level of protection as do native ants.
Tucson, Arizona, USA